This invention relates to a direct-current motor without commutator, with an armature, a detector for the armature position, and a motor winding arrangement which is supplied with current via a bridge network controlled by semiconductor switches acting in dependence upon the armature position, and having a device for the reduction of the current in the bridge network during the period of commutation of the current of the motor winding arrangement.
Such motors are known from the German Letters Patent No. 1208 803 and from the German Publication of Specification No. 25 085 46. To avoid, with the motors as known, short circuits during the period of commutation of the stator currents, which would bring about an impermissible load of the semiconductor switches and the source of the direct voltage, the bridge network therein (German Publication of Specification No. 25 085 46) is provided with 1 or 2 semiconductor switches (German Letters Patent No. 1208 803) in series, which will block the current to the bridge network at the respective moment of commutation. This known device is effective and prevents short circuits and consequential damages caused thereby. It is, however, expensive since, apart from the respective control devices, additional heavy duty, and thus expensive, semiconductor switches are required for the blocking of the total current to the bridge network.